diff --git a/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/c_GROUNDWATER_FLOW.md b/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/c_GROUNDWATER_FLOW.md
deleted file mode 100644
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..0000000000000000000000000000000000000000
diff --git a/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/i_process_variables.md b/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/i_process_variables.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/i_process_variables.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/t_process_variable.md b/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/t_process_variable.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/t_process_variable.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/c_STEADY_STATE_DIFFUSION.md b/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/c_STEADY_STATE_DIFFUSION.md
new file mode 100644
index 0000000000000000000000000000000000000000..3ba704b0d1ed80498a2d227efc5a7563891610c5
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/c_STEADY_STATE_DIFFUSION.md
@@ -0,0 +1 @@
+Steady state diffusion process described by a scalar, elliptic partial differential equation.
diff --git a/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/i_process_variables.md b/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/i_process_variables.md
new file mode 100644
index 0000000000000000000000000000000000000000..f2f28265edda7c6eb325c3504a209c211fe0ea74
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/i_process_variables.md
@@ -0,0 +1 @@
+The process variable for the steady state diffusion process.
diff --git a/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/t_process_variable.md b/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/t_process_variable.md
new file mode 100644
index 0000000000000000000000000000000000000000..641b29811bd382825b70a271e94a0c60c7965693
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/t_process_variable.md
@@ -0,0 +1,2 @@
+The scalar process variable for the steady state diffusion process, for instance
+temperature or pressure.
diff --git a/ProcessLib/SteadyStateDiffusion/CreateSteadyStateDiffusion.cpp b/ProcessLib/SteadyStateDiffusion/CreateSteadyStateDiffusion.cpp
index 704198846560505a2161bd768e63eda8472aac99..9b05c30e371df4f41231bc28c14736177739f813 100644
--- a/ProcessLib/SteadyStateDiffusion/CreateSteadyStateDiffusion.cpp
+++ b/ProcessLib/SteadyStateDiffusion/CreateSteadyStateDiffusion.cpp
@@ -57,14 +57,14 @@ std::unique_ptr<Process> createSteadyStateDiffusion(
 
     // Process variable.
 
-    //! \ogs_file_param{prj__processes__process__GROUNDWATER_FLOW__process_variables}
+    //! \ogs_file_param{prj__processes__process__STEADY_STATE_DIFFUSION__process_variables}
     auto const pv_config = config.getConfigSubtree("process_variables");
 
     std::vector<std::vector<std::reference_wrapper<ProcessVariable>>>
         process_variables;
     auto per_process_variables = findProcessVariables(
         variables, pv_config,
-        {//! \ogs_file_param_special{prj__processes__process__GROUNDWATER_FLOW__process_variables__process_variable}
+        {//! \ogs_file_param_special{prj__processes__process__STEADY_STATE_DIFFUSION__process_variables__process_variable}
          "process_variable"});
     process_variables.push_back(std::move(per_process_variables));
 
diff --git a/web/content/docs/tools/model-preparation/create-boundary-conditions-along-a-polyline/index.pandoc b/web/content/docs/tools/model-preparation/create-boundary-conditions-along-a-polyline/index.pandoc
index de12240699fbd9ccb1dcfe12b1e58205d9f7237e..5c10eac7ad8416204304581f5bb2449bf11ba895 100644
--- a/web/content/docs/tools/model-preparation/create-boundary-conditions-along-a-polyline/index.pandoc
+++ b/web/content/docs/tools/model-preparation/create-boundary-conditions-along-a-polyline/index.pandoc
@@ -12,7 +12,7 @@ author = "Thomas Fischer"
 
 The tool `CreateBoundaryConditionsAlongPolylines` searches for mesh nodes that are near to polylines and generates for each found node an OGS-5 boundary condition at a point.
 
-The user has to provide the input mesh `mesh` and the geometry `geometry` that must contain at least one polyline. Possible input formats for the mesh are the legacy OGS-5 mesh format or the vtu format. The geometry can be provided in the legacy OGS-5 gli format as well as in the gml format. The user can specify an environment via a search radius around the polyline. For all nodes within this environment boundary conditions are generated. Furthermore the type of the process the boundary condition is belonging to should be given. At the moment there are boundary condition output for LIQUID_FLOW (primary variable PRESSURE1) and GROUNDWATER_FLOW (primary variable HEAD) process avaible.
+The user has to provide the input mesh `mesh` and the geometry `geometry` that must contain at least one polyline. Possible input formats for the mesh are the legacy OGS-5 mesh format or the vtu format. The geometry can be provided in the legacy OGS-5 gli format as well as in the gml format. The user can specify an environment via a search radius around the polyline. For all nodes within this environment boundary conditions are generated. Furthermore the type of the process the boundary condition is belonging to should be given. At the moment there are boundary condition output for LIQUID_FLOW (primary variable PRESSURE1) and STEADY_STATE_DIFFUSION (primary variable HEAD) process avaible.
 
 The tool will output a OGS-5 boundary condition file (.bc) and a geometry file (.gli) containing the points the boundary conditions refer to. The original geometry will not be altered. Additional, it is possible to write the geometry in the gml format by setting the switch `gml` to 1.